Rectangles
What is the formula for finding the area of a rectangle?
Area = Length x Width (A=LxW)
What does the “l” and “w” stand for in the area formula A = L x W?
Length and Width
What does “composite shape” mean?
Two shapes together to make one shape.
Draw a rectangle with an area of 12 m².
1m x 12m
2m x 6m
3m x 4m
What is the formula for perimeter of a rectangle?
P = (L + W) x 2
P = 2 x (L +W)
Find the area of a rectangle with length 8 m and width 6 m.
48m2
True or False: The units of area are always written in “square units.”
True
Find the area of an L-shaped figure made from two rectangles: 6 m × 4 m and 4 m × 2 m.
32m2
If the area is 20 cm², name one possible set of side lengths.
1m x 20m
2m x 10m
4m x 5m
A rectangle has an area of 20 m². If one rectangle is 10 m × 2 m, what is its perimeter?
24m
A rectangle has an area of 45 m². If its width is 5 m, what is its length?
9m
A rectangle is 9 m long and 7 m wide. Write the formula with substitution before solving.
A = L x W
A = 9m x 7m
A = 63m2
A playground has a 10 m × 8 m rectangle joined to a 6 m × 5 m rectangle. Find the total area.
120m2
A rectangle has an area of 30 m². Give two different rectangles that fit this.
1m x 30m
2m x 15m
3m x 10m
5m x 6m
Two rectangles both have an area of 16 cm². One is 8 × 2, the other is 4 × 4. Compare their perimeters.
20m
16m
The first rectangle has a larger perimeter by 4m
The area of a rectangle is 72 m². One side is 12 m. What is the other side?
6m
Explain why we multiply length × width instead of adding them when finding area.
Area measures the inside, it shows how many squares are needed to fill the flat space. If we added the length and with, we would be measuring how long the outside length is - this is a perimeter.
An L-shape has an overall length of 12 m, height of 8 m, and an additional section of 4 m × 3 m. What is the area?
108m2
How many rectangles can you make with an area of 24 m² using whole numbers?
4
Which rectangle has the smallest perimeter: 12 × 3 or 6 × 6 (both with area 36 m²)? Why?
6m x 6m has the smallest perimeter because it is a square. Squares have smaller perimeters compared to long and skinny rectangles.
A rectangle’s length is 15 cm, and its width is 2 cm less than its length. What is the area?
195m2
Write the area formula for a rectangle and rearrange it to solve for width.
A = L x W
W = A ÷ L
Explain the strategy for finding the area of a composite rectangle.
You need to split the shape into two rectangles, find any missing or unknown lengths, then solve for each shape. Once you have the two areas, you add them together to find the total area of the composite rectangle.
The area is 36 cm². List at least three different rectangle dimensions that work.
5: 1m x 36m, 2m x 18m, 3m x 12m, 4m x 9m, 6m x 6m
Explain why a long, skinny rectangle and a nearly square rectangle with the same area can have very different perimeters.
Because skinny rectangles have longer sides, it adds more to the perimeter. Squares have shorter sides, so their perimeter will always be smaller than long, skinny rectangles.